1. Field of the Invention
The present invention is directed generally to a method and apparatus for cooling a structure using boiling fluid. More particularly, the present invention concerns a method and apparatus for cooling a structure having an actuator with a shaft and a fluid passageway connected to the shaft and in thermal communication with the structure.
2. Description of the Background
The need for an effective cooling apparatus exists in the field of x-ray tube technology. Conventional x-ray devices typically generate x-rays by an electron beam bombarding an anode. The anode is rotated at high speeds in order to distribute the heat that is generated by the impact of the electron beam over the surface of the anode. The electron beam striking the anode causes the temperature of the anode to increase. After a short period of operation, the x-ray tube must be shut-off for the anode to cool.
In the situation where the x-ray tube is used in a CT scanner, the x-ray tube is mounted in a housing and the housing is rotated 360 degrees around a patient to obtain a complete CT image of the patient. The x-ray tube of the CT scanner can be operated for only a short period and then the CT scanner must be turned off for an extended period to cool the anode. Usually, an adequate number of CT slices can not be obtained to form a complete CT image of the patient within the short period before the CT scanner must be turned off to cool the anode. In an emergency situation, doctors may have to wait a long period before they can obtain a complete CT image needed to diagnose and treat the patient. The delay in obtaining the complete CT image may be life threatening to the patient. In non-emergency situations, usually only four patients can be imaged per hour which results in the CT scanner remaining idle for a large portion of the life of the CT scanner. The CT scanner is an expensive piece of equipment and, therefore, it is undesirable to allow the CT scanner to remain idle. Yet another disadvantage of the conventional x-ray tube is the heat generated from the electron beam bombarding the anode degrades the bearings in the rotor and bearing assembly.
Accordingly, the related art does not provide an efficient method and apparatus for cooling an x-ray tube such that the x-ray tube can be continuously used for an extended period without cooling delays. Therefore, the need exists for a method and apparatus for cooling an x-ray tube that permits for continuous generation of x-rays without extended cooling delays, provides for greater cooling than the conventional x-ray cooling apparatus and reduces the complexity of the cooling equipment required to operate an x-ray tube.